Neutral scandium compounds having two univalent ancillary ligands or a bidentate, divalent ancillary ligand are known from Shapiro et al., Organometallics, vol. 9, pp. 867-869 (1990); Piers et al., J. Am. Chem Soc., vol. 112, pp. 9406-9407 (1990); Shapiro et al., J. Am. Chem Soc., vol. 116, pp. 4623-4640 (1994); Hajela et al., Organometallics, vol. 13, pp. 1147-1154 (1994); and U.S. Pat. No. 5,563,219 to Yasuda et al. Similar yttrium, lanthanum and cerium complexes are disclosed in Booij et al., Journal of Organometallic Chemistry, vol. 364, pp. 79-86 (1989) and Coughlin et al., J. Am. Chem. Soc., vol. 114, pp. 7606-7607 (1992). Similar polymerizations with a metal scandium complex having a bidentate, divalent ancillary ligand using a non-ionizing cocatalyst is known from U.S. Pat. No. 5,464,906 to Patton et. al.
Group 3-10 metallocyclic catalyst complexes are described in U.S. Pat. Nos. 5,312,881 and 5,455,317, both to Marks et al.; U.S. Pat. No. 5,064,802 to Stevens et al.; and EP 0765 888A2.
Polymerization of olefins with cationic Group 4 metal complexes is illustrated in WO 96/13529 and WO 97/42228. Boratabenzene complexes of Group 3-5 metals are disclosed in WO 97/23493.
Amidinato complexes of Group 3-6 metals are disclosed in U.S. Pat. No. 5,707,913 to Schlund et al. Group 4 bisamido catalysts are disclosed in U.S. Pat. No. 5,318,935 to Canich, et al., and related bidentate bisarylamido catalysts are disclosed by D. H. McConville, et al, Macromolecules 1996, 29, 5241-5243.